The study determined the loads of selected physicochemical components deposited with precipitation and carried away with outflow from two small catchments having similar habitat and climatic conditions but differing in land use and management pattern. The research was conducted in the hydrological years 2000 and 2001 in the Górka catchment (0.87 km²) and Barnczak catchment (1.21 km²) situated in the western part of the Małopolskie province (southern Poland). Samples of precipitation and outflowing water were collected twice a month on average. The concentrations of total suspended solids, ammonium and nitrate nitrogen, phosphates, dissolved substances, sulphates, chlorides, calcium, magnesium, potassium, manganese and iron were determined in a laboratory. These concentrations and the measured precipitation and outflows were used to compute the loads of the components, which were then compared between the two objects. For most components the loads carried away with outflow proved larger than those supplied by precipitation. The exceptions were ammonium nitrogen and manganese, whose removal was considerably smaller than supply, and in the Barnczak catchment also phosphates, with slightly smaller removal. The findings corroborated a thesis that precipitation constitutes an important source of non-point pollution, particularly with biogenic compounds. Larger loads of total suspended solids, ammonium nitrate, phosphates, potassium, manganese and iron flowed away from the Górka catchment having a higher proportion of built-up areas with disorderly water supply and sewage disposal management. The loads of the other components were bigger in the water flowing away from the Barnczak catchment, wholly used for agricultural purposes, with prevailing arable land.

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